For families that have babies, stroller is one of the most important equipments when the parents need to take the baby to the outdoors, such as go out for a walk or go shopping, etc. Because stroller is used to carry infants/babies, thus safety is the primarily concern in designing a stroller. Therefore, rules and regulations concerning the safety of strollers are made by the government for the stroller manufactures to follow and comply with so as to ensure the infants'/babies' safety. Additional to the safety, comfortableness and operational easiness are two essential issues of modern stroller design.
In order to increase the comfortableness of a stroller for infants/babies to ride in, the tilting angle of a stroller backrest is adjustable. For example, U.S. publication No. 2003/0052474 A1, published on Mar. 20, 2003, disclosed a stroller seat back leaning angle adjusting device which included a constraint element having a hollow body, two spring biased detent elements rotatably installed in the body, and two release elements operably coupled to the detent elements respectively, and two supporting straps on the seat back each having one end attached to a frame of the stroller and the other end inserted into the body from one side of the body, passing through a space between the detent element and the body and extending out of the body at the center of the body. In use, a user has to push the release elements simultaneously with one hand to drive the detent elements to overcome the biasing force so as to allow the detent elements disengaging the straps. At this time, the user need to use the other hand to either pull the free end of straps to tighten the straps for moving the seat back to an upright position, or to push the back downward to move the seat back to a tilted position.
Although this leaning angle adjusting device can perform a seat back leaning angle adjusting function, yet it has a disadvantage in operation. Specifically, the disengaging operation of the adjusting device and the angle adjusting operation are two independent operations in this design, thus a user need to use both his hands to complete a seat back leaning angle adjusting operation. This is inconvenience for a user using the stroller.
UK Patent No. GB 2375331A, published on Nov. 13, 2002, disclosed another stroller seat back tilting angle adjusting device. This adjusting device comprises a strap buckle fixed on a back side of the seat back, two straps for supporting the seat back each having one end thereof attached to a frame of the stroller and the other end being inserted through the strap buckle and locked to the strap buckle by a locking element after passing through a direction turning element. Similar to adjusting device described above, this seat back tilting angle adjusting device requires two hands to perform a smooth tilting angle adjusting operation. Specifically, while adjusting the tilting angle of the seat back, one hand is required to pull up the locking element to cause it disengaging with the straps, and then the other hand is required to either pull the free end of straps to tighten the straps for moving the seat back to an upright position, or to push the seat back downward to a desired tilting angle, and then push down the locking element back on so as to lock the straps to the buckle once again. Because the disengaging/locking operation of the buckle and the seat back angle adjusting operation are two independent operations, thus both user's hands are needed to perform a complete seat back leaning angle adjusting operation, and this is deemed inconvenience for a user to use the stroller.
In view of the inconvenience drawback in existing seat back leaning angle adjusting device of a stroller, there exists a need for seat back leaning angle adjusting device of a stroller which can adjust the leaning angle of the seat back in a simple and convenient way.